Device management apparatus, device initialization method, and device system

ABSTRACT

A device management apparatus that executes an initialization processing to a device that stores user data includes a first initialization processing section for executing a first initialization processing in which a progress status of an initialization is notified to another device management apparatus every time when the initialization equivalent to a processing unit of the initialization processing is executed to the device, a second initialization processing section for executing a second initialization processing in which a progress status of an initialization is notified to the another device management apparatus every time when the initialization for the predetermined number of processing units is executed to the device, a monitoring unit for monitoring a status of access to the device and an operation state of the device, and a changeover section for changing over the first initialization processing and the second initialization processing based on a monitoring result.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority of theprior Japanese Patent Application No. 2009-54188, filed on Mar. 6, 2009,the entire contents of which are incorporated herein by reference.

FIELD

Embodiment(s) discussed herein relate to a device managing apparatus, adevice initialization method, and a device system that execute aninitialization processing to a device that stores user data.

BACKGROUND

When a recording medium, such as a magnetic disc, an optical magneticdisk, an optical disc, or the like, is used as a device for storing userdata, it is required to preliminarily execute initialization of therecording medium, that is, format before actually writing user data.

Conventionally, it has been impossible to use the device before formatof the entire device is completed. Accordingly, there has been a problemin that the length of the time required for completing format is toolong. Consequently, a quick format for executing an initializationprocessing in a background of access to the device has been used.

In the quick format, in order to allow access right afterinitialization, a progress status of the initialization is managed byusing a bitmap or the like. Then, when access to a format uncompletedarea is required, the access is processed after the area ispreferentially formatted.

Herein, in a device system that has a plurality of device controlapparatuses managing access to a device and in which access to thedevice is duplicated, it is also required to duplicate the management ofthe progress status of the initialization. Consequently, in aconventional quick format, an update processing of a bitmap is executedand duplication of the bitmap is executed between the device controlapparatuses at a timing when initialization of an area equivalent to onebit in a bitmap is completed.

However, when considering the time required for duplication of theformat progress status, the time until the format is completed becomesshorter when the number of duplication of the format progress status tobe executed is low.

That is, when frequency of the duplication of the progress status isconsiderably higher than generation frequency of access to the deviceduring format, the time required for the format becomes long by theduplication processing. On the other hand, when frequency of theduplication of the progress status is considerably lower than generationfrequency of access to the device during format, a number of accessesare forced to wait, causing lowering of access responsiveness andoccurrence of time out. Further, since generation frequency of access isnot constant, it has been difficult to obtain the optimum one value asfor the timing for executing duplication of the format progress status.

The disclosed technique is made in the light of the aforementionedproblems, and the object is to provide to a device control apparatus, adevice initialization method, and a device system which make it possibleto shorten the time required for format while ensuring accessperformance to a device.

SUMMARY

A device management apparatus that executes an initialization processingto a device that stores user data includes a first initializationprocessing section for executing a first initialization processing inwhich a progress status of an initialization is notified to anotherdevice management apparatus every time when the initializationequivalent to a processing unit of the initialization processing isexecuted to the device, a second initialization processing section forexecuting a second initialization processing in which a progress statusof an initialization is notified to the another device managementapparatus every time when the initialization for the predeterminednumber of processing units is executed to the device, a monitoring unitfor monitoring a status of access to the device and an operation stateof the device, and a changeover section for changing over the firstinitialization processing and the second initialization processing basedon a monitoring result.

The object and advantages of the various embodiments will be realizedand attained by means of the elements and combinations particularlypointed out in the claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and arenot restrictive of the various embodiments, as claimed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram schematically showing the structure of a storagesystem which is an embodiment of a device system;

FIG. 2 is a diagram showing a concrete processing operation of a formatprocessing by a format processing unit;

FIG. 3 is a diagram showing a concrete example of changeover of a quickformat;

FIG. 4 is a flow chart illustrating a processing operation of the formatprocessing unit;

FIG. 5 is a flow chart illustrating a processing operation of a normalquick format by a normal quick format processing section;

FIG. 6 is a flow chart illustrating a processing operation of a highspeed quick format by a high speed quick format processing section;

FIG. 7 is a flow chart showing a processing operation when a localprogress status management is executed except a bitmap; and

FIG. 8 is a flow chart illustrating a write back processing shown inFIG. 4 in detail.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of a device management apparatus, a deviceinitialization method, and a device system disclosed by the inventionwill be described in detail based on the drawings. The invention is notlimited by the embodiment.

FIG. 1 is a diagram schematically showing the structure of a storagesystem which is an embodiment of the device system.

The storage system shown in FIG. 1 includes controller modules 10, 11which are examples of device management apparatuses. The controllermodule 10 is connected with storages 21, 22, each of which includes aplurality of data devices for storing user data. Similarly, thecontroller module 11 is also connected with the storages 21, 22, and thecontroller module 10 and the controller module 11 are connected via arouter 20.

The controller module 10 and the controller module 11 are respectivelyconnected with a host (not shown). Herewith, access to the storages 21,22 is duplicated.

The controller module 10 has a main controller 31, a memory 32, a hostinterface 33, and a device interface 34. The main controller 31 includesan access processing unit 41, a format processing unit 42, a devicestate monitoring unit 43. Each processing unit of the main controller 31may be respectively provided by a wired logic, a PLD (Programmable LogicDevice), or the like. The main controller 31 may be provided by anoperation device such as a CPU (Central Processing Unit) or the like andeach processing may be provided by software.

The access processing unit 41 receives an access requirement to thestorage from the host via the host interface 33, and processes theaccess to the storages 21, 22 via the device interface 34.

The format processing unit 42 is a processing unit that executes aninitialization processing of the device equipped in the storages 21, 22.The format processing unit 42 includes a format operation changeoversection 42 a, a normal quick format processing section 42 b, and a highspeed quick format processing section 42 c.

The normal quick format processing section 42 b and the high speed quickformat processing section 42 c respectively execute a quick format tothe storages 21, 22. Herein, the quick format is a format system forexecuting an initialization processing in a background of access to thedevice. The normal quick format processing section 42 b executes anormal quick format in which a progress status of the initialization isnotified to the controller module 11 which is another device managementapparatus every time when an initialization equivalent to a processingunit of the initialization processing is executed to duplicate theprogress status of the initialization. On the other hand, the high quickformat processing section 42 c executes a high speed quick format inwhich a progress status of the initialization is notified to thecontroller module 11 which is another device management apparatus everytime when an initialization for predetermined number of processing unitsof not less than two is executed to duplicate the progress status of theinitialization. The format operation changeover section 42 a changesover the normal quick format and the high speed quick format based onthe monitoring result by the device state monitoring unit 43.

The device state monitoring unit 43 monitors the generation status ofaccess to the storages 21, 22 and the operation state of the storages21, 22.

The memory 32 is a storage for holding various data used in thecontroller module 10. The memory 32 includes a cache 32 a, an IOprocessing status management table 32 b, a quick format management table32 c, and a quick format bitmap 32 d.

The cache 32 a is used when the access processing unit 41 processesaccess to the storages 21, 22. Specifically, the access processing unit41 holds an address of a writing destination and a content to be writtenin the storage when a writing request to the storage is received fromthe host, and returns a writing response to the host. Then, by executinga write back for actually writing the content held in the cache 32 a tothe storages 21, 22, the writing request from the host is reflected inthe storages 21, 22.

The IO processing status management table 32 b holds a monitored resultof the device state monitoring unit 43. Specifically, The IO processingstatus management table 32 b holds the type, response time, throughput,generation frequency of access, and the like of each device of thestorages 21, 22.

The quick format management table 32 c holds the information showingthat which device is a target of format when the quick format is beingexecuted by the format processing unit 42, a processing unit of theinitialization processing, that is, that one bit on the quick format bitmap 32 d corresponds to how much amount in the device, that each bit ofthe quid format bitmap 32 d corresponds to which address in the device,and the like. Note that, that one bit on the bitmap 32 d corresponds tohow much capacity on the device can be appropriately set. For example,one mega bits in the device correspond to one bit on the bitmap 32 d.

The quick format bitmap 32 d holds the progress status of the quickformat. One bit on the bitmap is a processing unit of the initializationprocessing, and that one bit corresponds to how much capacity in thedevice, and the correspondence relationship between each bit and thereal address in the device are regulated in the quick format managementtable 32 c.

The example is illustrated in which the cache 32 a, the IO statusmanagement table 32 b, the quick format management table 32 c, and thequick format bitmap 32 d are held in the same memory 32. However, adifferent storage may be provided for every information, or the cache 32a, the IO status management table 32 b, the quick format managementtable 32 c, and the quick format bitmap 32 d may be decentrally storedin a plurality of storages by any combination.

The controller module 11 has the inner structure similar to thecontroller module 10. Herein, the example in which there are twocontroller modules is illustrated. However, there may be not less thanthree controller modules.

FIG. 2 is a diagram illustrating a concrete processing operation of theformat processing by the format processing unit 42. First, the formatprocessing unit 42 transmits a format request to the storage 21. Theformat request is a writing request of initial data. As the initialdata, any data pattern can be used.

The storage 21 executes a format request, specifically, a writinginstruction of initial data in an area in the device corresponding to 1bit in the bit map, and returns a format response with respect to theformat request to the format processing unit 42 after the writingprocessing in the area in the device corresponding to 1 bit in the bitmap is finished.

The format processing unit 42 updates the quick format bitmap 32 d inresponse to the format response. Then, the format processing unit 42transmits a bitmap update content to the controller module 11. A maincontroller 51 of the control module 11 reflects the received updatecontent in a quick format bitmap 52 d in a self memory 52 to duplicatethe bitmap.

In the normal quick format, the normal quick format processing section42 b executes a format request, bitmap update, and bitmap duplicationfor every one bit of the quick format bitmap 32 d.

In the high speed quick format, the high quick format processing section42 c reduces the frequency of bitmap duplication as compared with thenormal quick format. That is, the high speed quick format processingsection 42 c executes bitmap duplication after the format equivalent toplurality of bits is executed. Accordingly, in the high quick format,the progress status of the format is grasped only at the controllermodule 10 side.

Note that the format request in the high speed format may be executedfor every one bit, or for several bits integrally. Further, the quickformat bitmap 32 d may be used for the management of the local progressstatus at the controller module 10 side. Further, the management of thelocal progress status may be held in the quick format management table32 c.

When a wiring request to the device executing the format from the hostis generated, the access processing unit 41 holds the content of writingrequest, that is, an address of a writing destination and a writingcontent in the cache 32 a, and returns a writing response to the host.Next, the access processing unit 41 specifies the bit indicating thecorresponding area with reference to the quick format management table32 c based on the writing destination address. Then, the accessprocessing unit 41 judges whether or not format of the writingdestination is completed based on the state of the bit corresponding tothe writing destination.

As a result, when format of the writing destination is completed, thedata in the cache is written in the device without change. When theformat of the writing destination is not completed, first, format isexecuted to the unit area that is managed by the bitmap including thewriting destination, and the data in the cache is written in the device.

In this manner, even when format is being executed, the writing requestfrom the host can be processed. However, when judging whether or notformat of the address of the writing request destination is completed,it is required that the progress status of the format is duplicated.

Accordingly, when the content in the cache is written in the device, itis necessary to wait for completion of the duplication of the progressstatus of the format. In the normal quick format, since duplication ofthe bitmap is executed at a high frequency, the waiting time until writeback is executed is short. However, when the generation frequency ofwrite back is low, the time for duplicating the bitmap itself becomes anextra time. In the high speed quick format, since the frequency ofduplication of the bitmap is low, the time for the entire format can beshortened. However the wait time until write back is executed becomeslong. Further, a number of accesses are forced to wait, causing loweringof access responsiveness and occurrence of time out.

Consequently, the format operation changeover section 42 a changes overthe normal quick format and the high speed quick format based on thegeneration status of the access to the storages 21, 22 and the operationstate of the storages 21, 22.

Specifically, the format operation changeover section 42 a changes overto the high speed quick format when there is no access from the host fora constant period, for example, several seconds to several minutes,during executing the normal quick format.

Then, during when the high speed quick format is executed, the formatoperation changeover section 42 a accumulates the writing request fromthe host in the cache 32 a during a constant period, for example,several seconds to several minutes, and stands by to write back to thedevice. Further, the format operation change over section 42 a canchange over to the normal quick format when the write cache reaches aconstant ratio of the entire cache 32 a.

Further, the format operation changeover section 42 a can judge thateffect to the host access by the high speed quick format is small whenthe access amount to the device from the host is not more than aconstant value during the normal quick format to change over to the highspeed quick format.

Further, the format operation changeover section 42 a can continue thehigh speed quick format when a response time or a throughput of thestorage shows a performance of not less than a constant value even whenthe high speed quick format is being executed, and can change over tothe normal quick format when there is a performance deterioration.Specifically, when the interface between the controller module and thestorage becomes a bottleneck than the interface between the controllermodules, it is no problem to execute a duplication processing by thecommunication between controller modules, and since reliability can beassured by the duplication processing, it is efficient to continue thehigh speed quick format until there appears a performance deteriorationin the processing with respect to the storage.

In this manner, the format operation changeover section 42 a optimizesthe resource in the apparatus without reducing access performance froman external part and without detracting reliability.

FIG. 3 is a diagram showing a concrete example of the changeover of thequick format. In the example shown in FIG. 3, the format processing unit42 starts format by the normal quick format first. In the normal quickformat, since update of the bitmap is constantly duplicated, the contentof the quick format bitmap 32 d of the controller module 10 and thecontent the quick format bitmap 52 d of the controller module 10 becomealways the same.

Then, the format processing unit 42 changes over from the normal quickformat to the high speed quick format when there is no input or outputfrom the host for a constant period. In the high speed quick format, itbecomes a simplex format in which only the controller module 10 locallymanages the progress status of the format. When the local management ofthe progress status is executed by using the quick format bitmap 32 d, atime lag is generated until the contents of the quick format bit map 32d and the quick format bitmap 52 d are matched. Further, when the localprogress status management is executed except the quick format bitmap 32d, the contents of the quick format bitmap 32 d and the quick formatbitmap 52 d are matched. However, a time lag is generated with respectto an actual progress status of the format.

The format processing unit 42 executes update and duplication of thebitmap every time the format is progressed by a predetermined amount.Further, when an access from the host is detected during the high speedquick format, the format processing unit 42 executes update andduplication of the bitmap for a part for which format is completed, andthen, changes over to the normal format.

Next, a processing operation of the format processing unit will befurther described with reference to FIG. 4. FIG. 4 is a flow chartillustrating the processing operation of the format processing unit 42.When the quick format is started, the format processing unit 42 firstmakes the normal quick format processing section 42 b execute the quickformat (S101). Then, the format processing unit 42 judges whether or notthe format of the entire device is completed (S102), and when the formatis completed (S102, Yes), the processing is finished.

On the other hand, when an area of an uncompleted format is remained inthe device (S102, No), the format operation changeover section 42 arefers to the cache 32 a and judges whether or not there is a writecache in the cache 32, that is, whether or not a writing request isgenerated (S103). When there is a write cache in the cache 32 a (S103,Yes), the format operation changeover section 42 a resets a timer(S107), makes the access processing unit 41 execute a write backprocessing (S108), and executes the normal quick format again (S101).

On the other hand, when there is no write cache in the cache 32 (S103,No), the format operation changeover section 42 a adds a certain valueto a timer value (S104), and executes the normal quick format (S101)when the value of the timer is less than a predetermined value (S105No).

Then, when the value of the timer becomes not less than a predeterminedvalue (S105, Yes), the format operation changeover section 42 a resetsthe timer (S106), and changes over to the high speed quick formatexecuted by the high quick format processing section 42 c (S110). Then,the format processing unit 42 judges whether or not the format of theentire device is completed (S111), and when the format is completed(S111, Yes), the processing is finished.

On the other hand, when an area of uncompleted format remains in thedevice (S111, No), the format operation changeover section 42 a refersto the cache 32 a, and compares the write cache amount in the cache 32 awith a predetermined threshold value (S112). As a result, when the cacheamount is less than the predetermined threshold value (S112, No), thehigh speed quick format processing section 42 c executes the high quickformat again (S110). On the other hand, when the cache amount is notless than the predetermined threshold value (S112, Yes), the formatprocessing unit 42 duplicates the progress status of the format (S113),and executes a write back processing of the data in the cache (S114),and returns to the normal quick format (S101).

FIG. 5 is a flow chart illustrating the processing operation of thenormal quick format executed by the normal quick format processingsection 42 b. First, the normal quick format processing section 42 bexecutes a format equivalent to one bit on the quick format bitmap 32 dwith respect to the device (S201), and updates the quick format bitmap32 d in the self controller (S202). Then, the normal quick formatprocessing section 42 b duplicates the bitmap (S203), and finishes thenormal quick format processing.

FIG. 6 is a flow chart illustrating the processing operation of the highspeed quick format executed by the high speed quick format processingsection 42 c. First, the high speed quick format processing section 42 cexecutes a format equivalent to predetermined number of bits on thequick format bitmap 32 d to the device (S301), and updates the quickformat bitmap 32 d in the self controller (S302). By the update of thebitmap, when the progress of the format that is not duplicated reaches apredetermined amount (S303, Yes), the high speed quick format processingsection 42 c duplicates the bitmap (S304), and finishes the high speedquick format processing. Further, when the progress of the format thatis not duplicated does not reach the predetermined amount (S303, No),the high speed quick format processing section 42 c finishes the highspeed quick format processing without change.

The processing operation shown in FIG. 6 is an operational example whena bitmap is used for locally managing the progress status. However, thelocal management of the progress status can be executed without using abitmap. FIG. 7 is a flowchart showing a progressing operation when thelocal management of the progress status is executed without using abitmap.

In the example shown in FIG. 7, the high speed quick format processingsection 42 c executes a format equivalent to predetermined number ofbits (S401), and locally updates the progress information (S402). Thelocal progress information may be created in, for example, the quickformat management table 32 c or the like.

Next, the high speed quick format processing section 42 c judges whetheror not the local progress reaches a predetermined amount (S403). Whenthe local progress reaches the predetermined amount (S403, Yes), thehigh speed quick format processing section 42 c updates the quick formatbitmap 32 d in the self controller (S404), duplicates the bitmap (S404),and finishes the high speed quick format processing. Further, when theprogress of the format that is not duplicated reaches the predeterminedamount (S403, No), the high speed quick format processing section 42 cfinishes the high speed quick format processing without change.

FIG. 8 is a flow chart illustrating the write back processing shown inFIG. 4 in detail. First, the format processing unit 42 judges whether ornot the format of the writing request destination of the write cache iscompleted (S501). As a result, when the format of the writing requestdestination is not completed, format of the bit including the writingrequest destination is executed by the normal quick format (S502).

After step S502, or when format of the writing request destination iscompleted (S501, Yes), the access processing unit 41 executes a writeback for reflecting the write cache to the device (S503), and the writeback processing is finished.

As described above, in the embodiment, in the case where there is noaccess to the device during the quick format for a predetermined period,the progress management of the quick format is executed by a simplex atthe controller module 10 side, and when the quick format is completed bya constant amount, the progress status is notified to the controllermodule 11 for duplication. In this manner, a necessary time of formatcan be shortened by changing the execution frequency of the duplicationprocessing of the progress status based on the generation status ofaccess and the state of the device.

Further, since format type is returned to the normal quick formatdepending on the frequency of access, the access performance to thedevice during executing the quick format can be assured.

Further, when the local management of the progress status is executedindependent from the bitmap, further speeding up of the processing canbe provided.

Similarly, during the high speed quick format, when format requests tothe device are collectively executed, a format range per one timebecomes large, so that the number of command processing between thecontroller module and the storage is reduced, the sequential property ofthe device inner operation is improved, and further speeding up theformat processing can be provided.

Note that in the embodiment, description is made for the embodiment inthe case where a bitmap is used for the management of the progressstatus. However, the disclosed technique is not limited to this, and anyprogress management can be applied. For example, the progress status offormat is managed by holding the final address of the format that issequentially executed and the address that is preferentially formattedby host access.

Similarly, the changeover of the normal quick format and the high speedquick format can be adequately combined for use according to thegeneration frequency and generation interval of access from the host,the operation state of the device, and the like.

The embodiments can be implemented in computing hardware (computingapparatus) and/or software, such as (in a non-limiting example) anycomputer that can store, retrieve, process and/or output data and/orcommunicate with other computers. The results produced can be displayedon a display of the computing hardware. A program/software implementingthe embodiments may be recorded on computer-readable media comprisingcomputer-readable recording media. The program/software implementing theembodiments may also be transmitted over transmission communicationmedia. Examples of the computer-readable recording media include amagnetic recording apparatus, an optical disk, a magneto-optical disk,and/or a semiconductor memory (for example, RAM, ROM, etc.). Examples ofthe magnetic recording apparatus include a hard disk device (HDD), aflexible disk (FD), and a magnetic tape (MT). Examples of the opticaldisk include a DVD (Digital Versatile Disc), a DVD-RAM, a CD-ROM(Compact Disc-Read Only Memory), and a CD-R (Recordable)/RW. An exampleof communication media includes a carrier-wave signal.

All examples and conditional language recited herein are intended forpedagogical purposes to aid the reader in understanding the principlesof the invention and the concepts contributed by the inventor tofurthering the art, and are to be construed as being without limitationto such specifically recited examples and conditions, nor does theorganization of such examples in the specification relate to a showingof the superiority and inferiority of the invention. Although theembodiment(s) of the present invention(s) has(have) been described indetail, it should be understood that the various changes, substitutions,and alterations could be made hereto without departing from the spiritand scope of the invention.

1. A device management apparatus that executes an initializationprocessing to a device that stores user data in a background of accessto the device, comprising: a first initialization processing sectionexecuting a first initialization processing in which a progress statusof an initialization is notified to another device management apparatusevery time the initialization equivalent to a processing unit of theinitialization processing is executed to the device; a secondinitialization processing section executing a second initializationprocessing in which a progress status of an initialization is notifiedto the other device management apparatus every time the initializationfor a predetermined number of processing units is executed to thedevice; a monitoring unit monitoring at least one of a generation statusof access to the device and an operation state of the device; and achangeover section changing over the first initialization processing andthe second initialization processing based on a monitoring result of themonitoring unit.
 2. The device management apparatus according to claim1, wherein the second initialization processing section individuallymanages the notified progress status and a progress status updated afterthe notification.
 3. The device management apparatus according to claim1, wherein the second initialization processing section updates theprogress status of the initialization every time when the initializationequivalent to the processing unit of the initialization processing isexecuted to the device, and notifies the other device managementapparatus of the progress status of the initialization every time theinitialization for the predetermined number of processing units of notless than two is executed.
 4. The device management apparatus accordingto claim 1, further comprising: a bitmap whose processing unit of theinitialization processing is one bit, wherein the first initializationprocessing section and the second initialization processing sectionmanage the progress status of the initialization processing by using thebitmap.
 5. The device management apparatus according to claim 1, whereinthe changeover section changes over the first initialization processingby the first initialization processing section and the secondinitialization processing by the second initialization processingsection based on an access request interval to the device.
 6. The devicemanagement apparatus according to claim 1, wherein the changeoversection changes over the first initialization processing by the firstinitialization processing section and the second initializationprocessing by the second initialization processing section based on astorage amount of a write cache to the device.
 7. The device managementapparatus according to claim 1, wherein the changeover section changesover the first initialization processing by the first initializationprocessing section and the second initialization processing by thesecond initialization processing section based on a processing state ofthe device.
 8. A device initialization method executed by a devicemanagement apparatus that executes an initialization processing to adevice that stores user data in a background of access to the device,comprising: a first initialization processing executing a firstinitialization processing in which a progress status of aninitialization is notified to another device management apparatus everytime the initialization equivalent to a processing unit of theinitialization processing is executed to the device to duplicate theprogress state of the initialization; a second initialization processingexecuting a second initialization processing in which a progress statusof an initialization is notified to the other device managementapparatus every time the initialization for a predetermined number ofprocessing units of not less than two is executed to the device toduplicate the progress state of the initialization; monitoring at leastone of a generation status of access to the device and an operationstate of the device; and changing over the first initializationprocessing and the second initialization processing based on amonitoring result of the monitoring.
 9. A device system equipped with adevice that stores user data and a plurality of device managementapparatuses for executing an initialization processing to the device ina background of access to the device, the device management apparatuscomprising: a first initialization processing section executing a firstinitialization processing in which a progress status of aninitialization is notified to another device management apparatus everytime the initialization equivalent to a processing unit of theinitialization processing is executed to the device, a secondinitialization processing section executing a second initializationprocessing in which a progress status of an initialization is notifiedto the other device management apparatus every time the initializationfor the predetermined number of processing units of not less than two isexecuted to the device, a duplication processing unit duplicating theprogress state of the initialization based on a notification from thefirst initialization processing section or the second initializationprocessing section of the other device management apparatus, amonitoring unit monitoring at least one of a generation status of accessto the device and an operation state of the device, and a changeoversection changing over the first initialization processing and the secondinitialization processing based on a monitoring result of the monitoringunit.